This exercise is great for shaping and strengthening the chest muscles. The chest is scientifically named the pectoralis. This muscle is used any time you push a chair up to the table, shut a car door, or push a shopping cart. There are two muscles that make up the pectoralis. They are the pectoralis major and minor. The pectoralis major is always the prime mover during chest exercises.

First, lie on a stability ball and place the weighted balls around the shoulder area. The ball should be positioned on your upper back. If the balls are in the right place, you should feel a light stretch in the chest muscles. The good thing about the stability ball is that it puts your spine in a safe and comfortable position to do the exercise. Next, press the weighted balls upward, just short of locking the elbows. Exhale as your arms go up. Then slowly lower the balls back to the starting position. You might choose to touch the balls together at the top of the movement. This is perfectly okay.